Every so often, system load on an e-Business Suite instance ramps up and response time to users starts climbing, often resulting in user observed errors such as:
- FRM-92100 Your connect to the server has been interrupted
- FRM-92102 A network error has occurred
Or sometimes, the screen just freezes (aka spins, stops, is broken, stuck, motionless, looks like a screen saver,can’t do anything, won’t work, froze-up, etc.) and the person has to close their browser, or even shut-down their workstation and restart.
Old technology often barks with unrelated error messages to the actual cause. If there’s a lot going on with concurrent requests, or interfaces, or analytic extracts running, the front-end response-time slows down, sometimes sufficiently to trigger these kinds of Form errors, even though technically there was no interruption to the network connectivity, either between the hosts, nor the workstation and the middle-tier application server.
However, on the database, the user-experience can be seen, although not necessarily in the place you might expect. OEM had introduced it’s Adaptive Metric Thresholds technology back in OEM 11g (in a slightly different place than in 12c (in Oracle Management Server/OMS 22.214.171.124.0). In OEM 11g, they were a link under the AWR Baseline Reports page.
In OEM 12c, you’ll find them under
Targets -> Database -> Peformance -> Adaptive Thresholds -> Baseline Metric Thresholds -> Edit Thresholds:
On this page and in the list of Baseline Metrics, when you click into them, you can access the trending statistics being gathered for each metric. Many times this will provide direct insight into what a user experiences as the “the system is frozen” translates into “the back-end database response time is incredibly bad.”
In the example here, the database experienced a dramatic slow-down in response almost 5 to 10 times slower than usual, which only lasted a few seconds. But that can be enough to show up in many users’ sessions who might have just kicked off a query, or were trying to save something. Based upon the information gathered, we set the Warning and Critical thresholds to 1500ms and 2000ms respectively to start sending e-mail alert notifications upon breach of the levels. If the settings are left at “None”, no incident would be raised, and thus, no notification would be sent.
If you’re experiencing odd transient outages or sluggish behavior that defies the normal AWR and ADDM snapshot analysis, go take a look at what OEM has been gathering in the background over time and see if the statistics correlate to any of your issues. There’s value in that data. Just mine it.